Angular motion Flashcards
Define angular motion
Movement around a fixed point
When does angular motion occur?
When a force is applied outside of the centre of mass
Define torque
The rotational consequence of a force
What can torque also be known as ?
Moment
Equation for torque
Moment or torque (Nm) = Force(N) X Perpendicular distance from fulcrum (m)
Newton metres NOT newtons per metre
What is newtons first law in relation to angular motion?
A rotating body will continue to turn about its axis with constant angular momentum until an external rotational force (torque) is exerted on it
What is newtons second law in relation to angular motion?
The rate of change of angular momentum of a body and its direction is proportional to the torque and its direction
What is newtons third law in relation to angular motion?
When torque is applied by one body to another, the second body will exert an equal and opposite torque on the other body
Define angular displacement
The smallest change in angle between the start and finish point of rotation
What is 1 radian equal to in degrees?
57.3 degrees
Define angular velocity
The rate of change of angular displacement
Equation for angular velocity
Angular velocity (rad/s) = Angular displacement (rad) / time (s)
Define angular acceleration
The rate of change of angular velocity
Equation for angular acceleration
Angular accleration (rad/s^2) = Change in angular velocity (rad)/time (s)
Define moment of inertia
Resistance of a body to angular motion
What 2 factors affect the moment of inertia?
Mass of the body
Distribution of mass around the axis
What is the effect of an increase in mass on moment of inertia?
Increases moment of inertia
How does a large distribution of mass affect the moment of inertia?
Greater distribution of mass increases moment of inertia
Define angular momentum
The quantity of rotation a body possesses
What is the equation for angular momentum?
Angular momentum = moment of inertia X angular velocity
What is the relationship between angular velocity and moment of inertia?
They are inversely proportional